Preparation and characterization of phosphoric acid cation exchangers from petroleum asphaltites

A phosphoric acid cation exchanger having an exchange capacity of 3.5 mg-equiv/g and a mechanical strength of 95% was prepared based on a graft copolymer of asphaltite and styrene using chloromethylation and then phosphorylation reactions. A number of metal chloride catalysts and the reaction kinetics of phosphorylation were studied. It was found that the resulting phosphoric acid cation exchangers are more stable than analogous commercial materials.     

Cotton fertilization with composts of (sugarbeet) vinasse and agricultural residues

A concentrated depotassified beet vinasse was mixed with each of ten solid agricultural residues. The ten mixtures were composted for 7 months. The composts obtained after this period were used to fertilize a cotton crop. A mineral treatment was used for comparison and a treatment without fertilization was used as control. The nitrate content of petiole determined before the first top dressing revealed significant differences between treatments. All treatments produced higher yields than the control. Analysis of fibre quality did not show significant differences between treatments.     

Preparation and characterization of PVC/PS composite cation exchange fibers and their adsorption properties on aniline

Based on the composite fibers made from polyvinylchloride (PVC) and polystyrene (PS), the composite fibers obtained were further crosslinked and sulphonated with 50% oleum to produce the acidic cation ion exchange fibers. The optimal technology of the fibers obtained were discussed, the structures of the fibers thus obtained were investigated by using Fourier transform infrared (FTIR) spectrophotometry, thermogravimetry analysis (TG), differential thermogravimetry analysis (DTG), and scaning electron microscope (SEM) etc. Their properties were measured using chemical titration, filament mightiness instrument, etc. The absorption kinetics and the main factors affecting absorption capacity on aniline were studied, and their regenerating properties were probed. The results indicated that the cation exchange fibers with better mechanical property and higher exchange capability were obtained. The fibers had bigger hydrophilicity, better ability of acid, and alkali corrosion resistance, so they had better practical application value. This type of ion exchange fibers had faster absorption property and better working stability to aniline and could be used repeatedly, so they were applied for treatment of waste water containing aniline with a promising prospect. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

QuECHERS-气相色谱法测定阿克苏特色农产品中的农残

建立QuECHERS-气相色谱法检测阿克苏特色农产品中25种农药残留量。样品用乙腈溶液振荡提取,QuECHERS净化,分别采用GC-ECD和GC-FPD检测,外标法定量。结果 25种农药在0.05～0.5mg/L线性关系良好,相关系数均大于0.990,加标浓度为0.05、0.1、0.2mg/kg,平均回收率在70.1～111.7%,相对标准偏差均小于15%,检出限在0.01～0.05mg/kg。该方法操作简便,准确可靠,稳定性强,适用于农产品中25种农药残留量的测定。     

废弃农林生物质在废水处理中环境友好利用的研究进展

综述近年来国内外利用废弃农林生物质环境友好处理各种废水的现状,重点阐述了废弃农林生物质作为吸附剂对印染、重金属等工业废水的处理以及通过改性手段来提高农林生物质处理效果的研究进展。     

Evaluation of acids and cellulase enzyme for the effective hydrolysis of agricultural lignocellulosic residues

This paper reports the results of experimentation carried out to compare the ability of mineral acids (HCl and H₂SO₄) and cellulase enzyme (from Trichoderma reesei QM 9414) in the saccharification of corn-cob, groundnut shell, sugarcane bagasse and wheat straw. With the exception of corn-cobs, acids proved to be better saccharifying agents than the cellulase complex, but the former gave a poor substrate for alcoholic fermentation since the saccharified mashes contained large amounts of pentoses which are not metabolized by most strains of yeast. In addition, both acids and enzymes have been found to be substrate specific. Maximal saccharification of groundnut shell, sugarcane bagasse and wheat straw were obtained with sulphuric acid at 15.0, 5.0 and 5.0% (v/v) under 15, 15 and 15 psi pressure for 15, 30 and 30 min, respectively; whereas hydrochloric acid at 7.5% (v/v) with. autoclaving for 30 min at 10 psi resulted in maximum saccharification of corn-cob. However, the order of susceptibility of substrates to enzymatic attack was corn-cob > wheat straw > sugarcane bagasse > groundnut shell. Increase in enzyme concentration (1–4 IU ml^?1) and treatment duration (12–72 h) improved saccharification, but increases in substrate concentration (>5.0%, w/v) had an inhibitory effect on the hydrolytic ability of the cellulase enzyme complex. Of the various substrate-acid ratios tested, a ratio of 1:8 was found to be optimal for the eflcient hydrolysis of the substrates under study.     

球形木素基正离子交换树脂的制备与性能

以木素磺酸钙为原料,在一种价廉无毒的分散介质中通过反相悬浮聚合制备了球形木素基正离子交换树脂。研究了分散介质和分散剂用量、聚合温度及搅拌速度等多种因素对聚合反应和成球效果的影响,并对交换树脂的形貌、粒径、含水量、密度、交换容量及吸附性能进行表征与测;定。结果表明,在实验室条件下,交换树脂对;Cr^3＋的饱和吸附量达到59．28mg／g（干树脂）。     

Preparation and characterization of anion exchangers from petroleum asphaltites

The chloromethylation reaction of an asphaltite and styrene graft copolymer followed by the amination of the chloromethylated products was optimized. New strongly basic anion exchangers with an exchange capacity of 2.5 mg-equiv/g and a mechanical strength of 93% were prepared.     

Preparation and characterization of a phosphonylated polypropylene ion exchanger

Because typical ion exchange resins used for treating wastewater contain sulfur binding sites and suffer from application limitations, a new ion exchange system was developed by phosphonylating nonwoven polypropylene fabric (PP). These fabrics were phosphonylated for 0.5, 1, 2, and 4 h; amount of phosphorus on phosphonylated PP increased with an increase in phosphonylation time. After hydrolysis, the appropriate phosphonylated sample was placed in a glass column where a europium (Eu³⁺), lead (Pb²⁺), or mercury (Hg²⁺) salt solution was passed through the fabrics after an equilibration period of 5 min. Filtrate samples were then analyzed by atomic absorption spectroscopy for metal concentration. Results showed that metal binding efficiency for Eu³⁺ increased with an increase in phosphonylation time; Pb²⁺ binding efficiency increased up to 2 h phosphonylation time and then decreased; Hg²⁺ binding efficiency was practically independent of phosphonylation time. PP fabrics were also sulfonated and tested for binding efficiency to determine if phosphorus was a better binding site than sulfur. By comparing the results from phosphonylated PP and sulfonated PP, data showed that phosphonylated PP bound metal ions at a higher efficiency than sulfonated PP. Also, phosphonylated PP had higher binding efficiencies with Eu³⁺ and Pb²⁺ than a commercial exchange resin. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 93–100, 2000     

中空聚丙烯基离子交换纤维的制备及表征

以CaCO_3为成孔剂,通过共混熔融纺丝和酸化制备中空聚丙烯纤维,以纤维为基体,通过引发剂接枝苯乙烯,再经氯甲基化和胺化反应制备强碱性阴离子交换纤维;采用红外光谱、电镜扫描、热重分析等分析手段对制备的离子交换纤维进行了表征,并对其交换容量、溶胀性及动力学吸附性能进行了测试。结果表明:制备的强碱性阴离子交换纤维具有较高的交换容量,约达到3.08 mmol/g,吸附性能良好,含水量大于56%,是一种性能优良的离子交换纤维。     

Conversion of agricultural residues into cation exchange materials

A series of cation exchange resins were prepared from some low-value agricultural residues. Carboxylate (maleate, succinate, and phthalate), phosphate, and sulfate groups were incorporated onto the complex polysaccharide matrix of oat hulls, corn cobs, and sugar beet pulp. Standard reaction conditions were established, using cellulose as the model polysaccharide. The magnitude of functional group incorporation, under standard conditions, was taken as a measure of the reactivity of the agricultural residues studied. In general, the order of reactivity was sugar beet pulp > corn cob > oat hull. The unsubstituted and the functionalized agricultural residues were tested for their potential ability to remove cations from waste water discharges. The capability of these materials to remove cations from waste waters was estimated from their calcium binding capacity. The calcium binding capacities of the resins prepared from the agricultural residues varied from around 559–3466 μequiv/g. © 1996 John Wiley & Sons, Inc.     

Copolymers of haemin and vinyl monomers as cyanide ion exchangers: Modifications of the ion exchange properties by introduction of acrylamide residues

Ternary copolymers of haemin (H) and styrene (St) with acrylamide (AAm), copoly(H, St, AAm), and with 1-vinyl-2-pyrrolidone (VP), copoly(H, St, VP), were synthesized by radical copolymerization. It was found that the H content of the resulting copolymer generally agrees with that of the corresponding monomer feed. Moreover, the yield and reduced viscosity decrease in proportion to the feed concentration of the H monomer. Each copolymer prepared showed hydrophilic character compared with the copolymer of H and St. The adsorption of cyanide ion onto the copolymer was investigated at different pHs to clarify the functional capability as cyanide ion exchanger. The amount of cyanide ion adsorbed on 1 g dry polymer (A_cn in mg/g) was found to be dependent on the H content of the copolymer, thus indicating that the haem-iron is the adsorption site of the cyanide ion. From the curves of A_cn against the AAm or VP content of the copolymer and against pH for copoly (H, St, AAm) and copoly(H, St, VP), it was observed that the adsorptive capacity of the cyanide ion is increased by the introduction of the AAm residue. The same result was obtained for column experiments. These results were discussed in connection with the reaction of a cyanide ligand with the haem-iron site in the copolymer.     

用有机硅高沸物生产硅油的方法

合成甲基氯硅烷的副产物有机硅高沸物经甲醇醇解、中和静置分层、过滤后，制得硅油产品；分析了影响硅油粘度的因素。结果表明：按高沸物100份、甲醇50～60份、中和剂A60～70份、中和剂B30-40份、助熔剂6～8份的配比，能制得粘度大于10mm^2／s的系列硅油产品。     

Preparation and characterization of UV‐grafted ion‐exchange textiles in continuous electrodeionization

Ion‐exchange textiles (IETs) suitable for use in continuous electrodeionization (CEDI) stacks were prepared using the ultraviolet (UV)‐induced grafting of acrylic acid and sodium styrene sulfonate for cation‐exchange textiles, or 2‐hydroxyethyl methacrylate and vinylbenzyl trimethyl ammonium chloride for anion‐exchange textiles, onto nonwoven polypropylene fabric using benzophenone as photoinitiator. Although the ion‐exchange capacity (2.2 meq g^?1) of the prepared strong acid cation‐exchange textile was lower than that of IRN77 strong acid cation‐exchange resin (4.2 meq g^?1), the overall rate constant of IET was very high due to its low crosslinking and high specific surface area. There was no significant difference between the two different media in terms of the Co(II) removal rate. Furthermore, the current efficiency for IETs was higher than that of IRN77 cation‐exchange resin during a CEDI operation, with efficiencies of 60% and 20%, respectively. The IET also showed the faster exchange kinetics. Therefore, IETs prepared in this study proved to have desirable ion‐conducting characteristics within the CEDI systems. Also this study revealed that the primary removal mechanism in CEDI is the transport of ions through a medium and not the ionic capacity of a medium. Copyright © 2004 Society of Chemical Industry     

Preparation and some applications of phosphosulfonated bagasse and wood pulp cation exchangers

Cation exchangers are prepared by phosphorylation and by sulfonation as well as by incorporating both phosphate and sulfonate functional groups on bagasse and wood pulp. The optimal composition of the acid mixtures used for the preparation of these ion exchanger was determined. Possible applications of these ion exchangers in columns and for some industrial uses were investigated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 97–104, 2003     

竹屑常压酸催化液化产物的制备与表征

在常压酸催化作用下对竹屑进行多元醇液化,对液化产物的羟值和粘度进行了测定,并通过红外光谱、凝胶渗透色谱及GC-MS等对液化产物进行分析表征。结果表明:液化产物的羟值为350mgKOH/g,粘度为750mPa·s,相对分子质量分布范围在18~20 372之间,为连续分布形式,满足制备中强度硬质聚氨酯泡沫的要求。     

Kinetic separation of cobalt from zirconium by cation exchange process

Zirconium-tin alloys are used as pressure tubes in Indian pressurized heavy water reactors (PHWRs). Used pressure tubes contain neutron activation products of the constituent elements. ⁶⁰Co is one of the long-lived radioisotopes of concern, for both radioactive waste management and recycling of pressure tubes. This article describes a facile cation exchange separation of Co(II) from Zr(IV) in HCl medium. Co(II) could be preferentially sorbed on the gel resin by utilizing its faster kinetics. Higher flow rates and shallow resin bed were the key steps, which prevented the loading of Zr(IV) on the resin phase.     

农林废弃物制备活性炭的化学方法

综述了三种化学活化法制备活性炭的方法及其效果,并分析了化学活化法的优缺点,为今后制备活性炭提供了参考。     

离子交换法制备LiNbO_3超细粉体及其表征

以草酸锂和草酸铌为原料,少量水为溶剂,充分研磨干燥后得到前驱体。利用红外光谱(FTIR)、热重分析(TG)技术对前驱体进行分析可知,草酸锂和草酸铌在研磨过程中发生了离子交换反应。将制备的前驱体分别在500,800℃下焙烧3 h,得到单相LiNbO3和(Li0.996Nb0.005)Nb0.999O3晶体。通过X-射线衍射仪(XRD)、扫描电镜(SEM)及FTIR对产物进行表征,当焙烧温度为500℃时得到的LiNbO3晶体,具有较高的相对结晶度(87%)和较小的粒径(<100 nm)。     

Dynamic mechanical properties of agricultural residues‐filled polystyrene

Agricultural residues (cotton straw) were added as very small particles to polystyrene (PS) at different weight ratios by using a melt‐mixing technique. The dynamic mechanical tests were performed over a wide range of temperatures and frequencies by using an ARES rheometer (Rheometrics Scientific) operated in the dynamic mode. The dynamic mechanical properties in terms of the storage modulus (G′), loss modulus (G″), compliance moduli, loss tangent, and dynamic viscosity were studied and compared for PS and PS composite. The results showed that the dynamic mechanical moduli and viscosity were found to increase with the addition of cotton straw and rise further with its loading increasing. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 37–40, 2004